Biomedical subjects

B Curran

Publications and source records attributed to B Curran.

At least 37 records · Page 2Linked to original sources

PubMed1994

Toe pressure determination by audiophotoplethysmography.

PURPOSE: The purpose of this study was to evaluate the performance of audiophotoplethysmography as a modality to measure toe pressure without the requirement of a recorder. METHOD: A portable photoplethysmograph with an audio output was used to determine toe pressures, and the results were compared with those obtained by a commercial photoplethysmograph with a recorder. RESULTS: Thirty-one measurements in control subjects and 62 measurements in patients with arterial occlusive disease were performed. The average toe pressure recorded with oscillography with standard photoplethysmography was 103.5 mm Hg +/- 14.7 SD and 95.9 mm Hg +/- 13.4 SD with audio-photoplethysmography. In the patient group the pressure recorded with a commercial photoplethysmograph was 65.3 mm Hg +/- 34.9 SD compared with 61.6 mm Hg +/- 34.8 SD obtained with audio-photoplethysmography. The difference in both groups was insignificant, and the correlation between both methods was very good. CONCLUSION: A portable hand-held photoplethysmograph equipped with an audio output was used to measure toe pressure in control subjects and in patients with arterial occlusive disease. The results have been compared with the oscillometric method by a standard commercial photoplethysmograph connected to a recorder. The correlation was very good in the control and patient groups, and the difference between both methods was below the level of statistical significance. The fact that no recorder is needed may help in introducing toe pressure measurement into everyday office diagnostic practice.

Arterial Occlusive Diseases↗

PubMed1994

C-erbB-2 immunostaining: problems with interpretation.

AIMS: To assess the consistency and reproducibility of assessment of c-erbB-2 immunostaining, and to examine some of the problems relating to inter- and intraobserver variability in the documentation of positive staining; to profile the spectrum of cytoplasmic and membranous staining in a wide range of tumour types. METHODS: A total of 283 neoplasms were examined for immunohistochemical expression of the c-erbB-2 oncoprotein. Three independent observers were required to assess intensity both of membrane and cytoplasmic staining on a three point and then a four point scale. Extent of positive staining was also assessed on a two point scale. A minimum of two weeks elapsed between assessments using the differing scales. RESULTS: Positive membrane staining was documented by one or more observers in 16.6% of tumours examined. This positivity was largely restricted to bladder, renal, and breast tumours. The overall level of disagreement as to the presence or absence of membranous staining was 11.3%. Cytoplasmic staining was identified in 55.5% of tumours studied. The level of disagreement as to the presence or absence of cytoplasmic staining was 26.5%. CONCLUSIONS: Intraobserver variability was minimal, indicating that each pathologist was adhering to internal reproducible standards. Interobserver variability was greater, indicating that the interpretation of c-erbB-2 immunostaining may require set guidelines. It is suggested that assessment should be referenced to a standard positive control, that a three tier system for grading of intensity and a two tier system for grading of extent should be adopted, and that the evaluation should be agreed by at least two pathologists. The presence of cytoplasmic staining should continue to be routinely recorded until its biological role and clinical implications are fully understood.

Biomarkers, Tumor↗

PubMed1993

Deoxyribonucleic acid ploidy studies in choroidal melanomas.

In several tumors of different organ sites, the amount of DNA in a cell (ploidy) is associated with malignancy. We performed DNA quantitation in 21 choroidal melanomas and compared flow cytometry with image analysis in 11 of these melanomas. We modified our preparation technique to overcome problems with pigment and control cell populations in the image analysis group. Fifteen tumors were diploid and two tumors were tetraploid. Four tumors were unprocessable by flow cytometry, but two of these tumors were diploid by image analysis. Image analysis also detected tetraploidy in two tumors that were diploid by flow cytometry. During image analysis, cells were classified according to the Callendar classification and histograms were plotted for each cell type. All spindle A cells were diploid and most tetraploid peaks were formed by epithelioid cells. The use of image analysis on small samples of choroidal melanomas may be of value both in confirmation of diagnosis and prognosis of these lesions, and perhaps therapeutically, for example, in the monitoring of radiation treatment.

Choroid Neoplasms↗

PubMed1993

c-myc expression in renal carcinoma: correlation with clinical parameters.

There is evidence that c-myc is expressed in renal carcinomas and that it is associated with histological grade. This study reports on the clinical correlations of oncogene expression and clinical features of the disease. Tissue sections from 97 patients (95 primary and 12 secondary cancers) were immunostained with a c-myc oncoprotein antibody. The tumours were scored for extent and intensity of nuclear and cytoplasmic staining. Ninety patients were suitable for follow-up study. High levels of expression correlated significantly with increasing T category and nuclear grade, as well as with venous invasion. No correlation with nodal involvement, the presence of metastases, tumour architecture or cell type was found. The extent of nuclear staining was related to survival (although not to recurrence), but in a multivariate analysis did not provide independent prognostic information. It was concluded that semiquantitative assessment of levels of c-myc oncoprotein does not provide clinically useful prognostic information.

Adult↗

PubMed1993

Ploidy and prognosis in renal carcinoma.

The value of tumour ploidy status as a prognostic indicator in renal carcinoma is disputed. In this retrospective study the DNA content of 90 primary and 10 secondary renal cell carcinomas was measured using flow cytometry. Data on recurrence and survival were available in all cases. Tumours were staged according to the TNM system and histological grade was based on nuclear morphology. Formalin-fixed, paraffin-embedded material was processed using standard techniques. Multiple samples were examined in 19 cases. Of the primary tumours, 52 were diploid, 24 were aneuploid and 6 were tetraploid; 8 patients had uninterpretable histograms. Ploidy of the secondary tumours was similar to that of their respective primaries. Aneuploidy correlated with higher grade but not with TNM category and, although associated with an increased risk of death, did not provide independent prognostic information. Heterogeneity of ploidy was found in 6 of the 19 cases where more than 1 sample was assessed. It was concluded that tumour DNA content in renal carcinoma is weakly linked to outcome, is subject to sample error and does not provide accurate prognostic information as a single independent variable.

Adult↗

PubMed1993

Comparison of flow and static image cytometry in the determination of ploidy.

AIMS: To compare the efficiency of flow cytometry and computed image cytometry; and to see if a reliable set of guidelines regarding interpretation of histograms could be drawn up. METHODS: The two methods were applied to a series of 111 formalin fixed renal cell carcinomas. Data generated by both methods were compared. RESULTS: The methods agreed in 85 cases. Hypodiploidy was detected by computed image cytometry in seven cases in which flow cytometry had shown only an aneuploid peak. Aneuploidy in seven in which the corresponding flow cytometry histogram was diploid. There was an overlap in the second peak proportions on flow cytometry histograms between those classed as diploid or tetraploid by computed image cytometry. In six cases the flow cytometry histograms had unacceptably high coefficients of variation and in all of these cases computed image cytometry demonstrated aneuploidy. CONCLUSIONS: Computed image cytometry is particularly useful for clarifying difficult areas in flow histograms--specifically, high coefficients of variation, high G2M phase, as well as possible near diploid aneuploidy and hypodiploidy.

Carcinoma, Renal Cell↗

PubMed1993

Partial hydatidiform mole: a common but underdiagnosed condition. A 3-year retrospective clinicopathological and DNA flow cytometric analysis.

This retrospective study reports the incidence of hydatidiform mole in a population of 19,457 pregnancies over a 3-year period. During the study period all "products of conception" from first and second trimester abortions were referred for pathological examination. Coded histologic sections were reviewed using the published histologic criteria for hydatidiform mole. Ploidy was estimated by DNA flow cytometry. Clinical data were retrieved from maternal case notes. Thirty-eight cases were confirmed as hydatidiform mole, 10 (26%) as complete mole, and 28 (74%) as partial mole. Twenty-three cases of partial mole (88%) were triploid, and nine of 10 complete moles were diploid. The incidence of hydatidiform mole was 1:512 pregnancies, (complete mole, 1:1,945; partial mole, 1:695). Only one case (3.5%) of partial mole was suspected clinically. One case of persistent gestational trophoblastic disease occurred following a complete mole. No sequelae were encountered following partial mole. We conclude that hydatidiform mole is a common condition and the majority of cases are partial moles. Quantitatively imprecise morphologic criteria contribute to the inaccuracy in reporting of partial mole; analysis of ploidy is useful in the evaluation of problem cases. Follow-up of partial mole is warranted because its true biological potential is as yet unclear.

Abortion, Spontaneous↗

PubMed1992

DNA quantification of squamous cell carcinoma of the oesophagus by flow cytometry and cytophotometric image analysis using formalin fixed paraffin embedded tissue.

This is the first comparative study of DNA quantification of oesophageal squamous cell carcinoma by flow cytometry (FCM) and image cytometry (ICM) using formalin fixed paraffin embedded tissue. The potential advantages of ICM include the identification of a reliable control cell population; avoidance of non-tumour stromal and inflammatory cell nuclei, nuclear fragments, degenerate cell nuclei and doublets, triplets etc., which are not possible with FCM using archival tissue. Twenty-eight cases, all of the same stage (stage 2a) and similar grade (well or moderately differentiated) were analysed. The cases were separated into two groups, those that had succumbed to tumour in less than 18 months (group A) and those that were tumour free at least 18 months post-resection (group B). Using ICM all 28 tumours yielded interpretable histograms by comparison to 25 of 28 using FCM. Aneuploidy was identified in 100% of cases in group A using ICM (in comparison to 73% by FCM) and in 73% of group B using ICM (in comparison to 44% by FCM). Any tumour aneuploid by FCM was also aneuploid by ICM. Nine cases aneuploid by ICM were euploid by FCM. The mean 5C exceeding rate (% of cells whose nuclei contain a DNA mass equivalent to > 5 sets of 23 chromosomes) was 21% in group A and 14% in group B (P < 0.01). Euploidy was confined to tumours of those patients disease free for more than 18 months. The conclusions of this study are that: firstly, ICM is superior in its yield of interpretable histograms to FCM using formalin fixed paraffin embedded tissue; secondly, ICM is more sensitive in the identification of aneuploid stemlines than FCM; and thirdly, euploid tumours (as detected by ICM) appear to have a better prognosis than aneuploid tumours of similar stage and grade.

Adult↗

PubMed1992

DNA ploidy in squamous oesophageal carcinoma.

The role of DNA ploidy in the management of oesophageal carcinoma is unclear. Most studies have employed flow cytometry (FC) for DNA analysis but some have used image analysis (IA) of tissue sections. In this study aneuploidy rates in stage IIa squamous tumours were determined by both FC and IA of cell suspensions and results were compared with outcome in two patient subgroups. Group 1 (n = 15) were patients who died from tumour recurrence within 1 year of surgery while Group 2 (n = 21) were patients who survived tumour free for at least 1 year. Aneuploidy rates differed significantly between techniques; 29 of 36 tumours (81%) were aneuploid by IA compared with 19 of 34 (56%) by FC (P < 0.05). Aneuploidy rates differed significantly between groups 1 and 2 as determined by FC (79%) versus 40%) (P < 0.05) but not by IA (93% versus 71%) (P = ns). Euploid status was a good prognostic indicator; 6 of 7 (86%) patients with euploid tumours by IA and 12 of 15 (80%) by FC (P < 0.05) survived more than 1 year. The sensitivity and specificity of euploidy was 93% and 28.6% for IA compared with 78.6% and 60% for FC. Since 33 (92%) of these tumours exhibited a marked peritumoral desmoplastic or chronic inflammatory reaction IA, being more sensitive to subtle nuclear change, may be a more appropriate technique than FC for evaluation of the role of ploidy in such tumours.

Adult↗

PubMed1992

Defining conditions for the efficient in vitro cross-linking of proteins to DNA by chromium(III) compounds.

The formation of cross-links between bovine serum albumin and DNA in the presence of chromium(III) chloride was found to be highly pH dependent. In vitro, such lesions were only formed at acidic values of pH, but were not detected at neutral pH. Complexes of chromium(III) and GSH/GSSG similarly failed to induce DNA-protein cross-links at physiological values of pH. Our findings indicate that the cross-links generated in vitro at acidic pH may not be directly relevant to the observed formation of such lesions in cultured cells and that a physiologically relevant in vitro model for the efficient cross-linking of proteins to DNA has yet to be devised.

Bacteriophages↗

PubMed1992

DNA quantitation of Wilms' tumour (nephroblastoma) using flow cytometry and image analysis.

AIMS: To compare flow cytometry (FCM) with image analysis (IA) in the DNA quantitation of Wilms' tumour (WT) and to correlate data so obtained with recognised clinical and pathological prognostic parameters. METHODS: Thirty six patients with histologically proved WT diagnosed between 1980-89 were investigated. Fifteen patients had stage I disease, 10 stage II, six stage III, two stage IV and three stage V. Suspension of nuclei obtained by pepsin digestion of paraffin wax embedded tumour tissue was analysed using a FAC-Scan flow cytometer, and a CAS-100 image analyser. RESULTS: Tumours were concordant in most instances, however, IA identified aneuploidy in two tumour samples which were diploid by FCM. Aneuploidy was detected in 5/33 tumours with favourable histology and 3/3 with unfavourable histology. Three of 28 patients with Stage I, II and V disease and 5/8 patients with stage III and IV had aneuploid tumours. All patients with unfavourable histology died of disease. In the group with favourable histology, 4/5 patients with aneuploid tumours developed recurrent disease compared with 1/27 diploid tumours (p less than 0.0001). CONCLUSIONS: Ploidy may be a useful additional prognostic indicator in Wilms' tumour with favourable histology. Larger scale studies are needed to confirm the relation of ploidy to survival in early stage WT.

Child↗

PubMed1991

Mac387: its non-specificity as a tumour marker or marker of histiocytes.

A commercially available monoclonal antibody which detects histiocytes in paraffin sections, Mac387, was reacted with 148 soft tissue sarcomas, 29 carcinomas and 10 malignant melanomas. The soft tissue sarcomas had been previously immunophenotyped. All categories of sarcomas, with the exception of angiosarcomas, were positive. Most showed staining in less than 50% of the tumour cells. Six of 10 adenocarcinomas and three of nine basal cell carcinomas were positive, while squamous carcinomas and malignant melanomas were negative. Normal squamous mucosa and epidermis were also positive. The results of this study suggest that Mac387 is of little value in the differential diagnosis of soft tissue tumours, nor is it a specific histiocytic marker.

Antibodies, Monoclonal↗

PubMed1991

The prosthetic treatment of upper limb deficiency.

The provision of prostheses for children with upper limb deficiency starts at an early age. The roles of the occupational therapist and prosthetist in this programme are described. Casting and fitting techniques applicable to transverse forearm loss and aspects of myoelectric hand prostheses are included. An outline of training methods as related to both parent and child is explained. Higher levels of limb deficiency are covered briefly and the use of alternative methods of electric hand control is included. Finally, a brief summary of distal deficiency is discussed.

Arm↗

PubMed1990

Review of an Irish cervical smear service.

Cervical cytology material from 5,815 women who presented to General Practitioners throughout Ireland for routine cervical smears were referred to our Pathology Laboratory. The smears were reviewed retrospectively in order to report on the incidence of dyskaryosis and other abnormalities diagnosed on cervical cytology. Evidence of dyskaryosis was found in a total of 2.2% and "borderline" changes in a total of 0.3% of smears. Cytology and subsequent histology were compared in cases of significant cervical intraepithelial neoplasia. Comparison in cases of moderate and severe dyskaryosis showed precise correlation between the diagnosis of cervical intraepithelial neoplasia on biopsy and its prediction on cytology in 30 of 33 cases. Over a third of women screened were in their 4th decade and the highest incidence of dyskaryosis was in this age group. Only 10% of those screened were 50 years or over and a third were aged 40 years and over. These facts are of relevance with regard to the problem of targeting the population at risk in the long term planning of routine cytology screening services in this country.

Adolescent↗

PubMed1990

Ploidy of smooth muscle tumours: retrospective image analysis study of formalin fixed, paraffin wax embedded tissue.

The feasibility of using an image analyser, the CAS 100, to assess the ploidy of smooth muscle tumours on formalin fixed paraffin wax embedded tissue was assessed. Various different methods of assessment were compared. A paraffin wax block of 15 leiomyomata and 13 leiomyosarcomata yielded serial sections of 3 microns, 5 microns, and 7 microns and a cytospin preparation (from a 50 micron section). Sections and cytospin preparations were stained with Feulgen and quantified using the CAS 100. The suitability of lymphocytes, previously suggested to be unsuitable as control cells in tissue sections due to the compact nature of their DNA, was assessed in sections and cytospin preparations and compared with endothelial cells, the standard alternative, on the same slide. Despite having a mean nuclear area of only 18.5 microns 2 in sections lymphocytes had a similar diploid peak--that is, 4.1 pg--to endothelial cells (mean nuclear area 39 microns 2). A comparison of 3 microns, 5 microns, and 7 microns sections showed 5 microns to be the optimal thickness. Cytospin preparations yielded histograms of superior quality than those from tissue sections. All 15 leiomyomata had a 5C exceeding rate of less than 0.3%. Ten of 11 histologically malignant tumours had a 5C exceeding rate of more than 5% (mean 14%) in sections and cytospins. Two leiomyosarcomata that had arisen in the lower gastrointestinal tract had a mitotic rate of less than or equal to 1/10 per high power fields and yielded histograms similar to those of the leiomyomata. It is concluded that formalin fixed, paraffin wax embedded tissue can be used for DNA quantification by image analysis; that tissue sections yield poorer results than cytospin preparations; that lymphocytes are reliable control cells in cytospin preparations; and that a population of cell greater than 5C is seen in 90% of leiomyosarcomata.

Cell Separation↗

PubMed1989

Determination of adult stature from metatarsal length.

The results of a study to determine the value of foot bones in reconstructing stature are presented. The data consist of length measurements taken on all ten metatarsals as well as on cadaver length from a sample of 130 adults of documented race, sex, stature, and, in most cases, age. Significant correlation coefficients (.58-.89) are shown between known stature and foot bone lengths. Simple and multiple regression equations computed from the length of each of these bones result in standard errors of estimated stature ranging from 40-76 mm. These errors are larger than those for stature calculated from complete long bones, but are approximately the same magnitude for stature calculated from metacarpals and fragmentary long bones. Given that metatarsals are more likely to be preserved unbroken than are long bones and given the ease with which they are accurately measured, the formulae presented here should prove useful in the study of historic and even prehistoric populations.

Adult↗

PubMed1989

Electron microscopy of adhesive interactions between Gardnerella vaginalis and vaginal epithelial cells, McCoy cells and human red blood cells.

Exfoliated vaginal epithelial cells with attached bacteria, termed 'clue cells', which were procured from a patient with non-specific vaginitis, were stained with ruthenium red and examined by transmission electron microscopy. The attached bacteria appeared to adhere by means of an outer fibrillar coat. An epithelial tissue culture cell line (McCoy) and human red blood cells to which strains of Gardnerella vaginalis attached were similarly examined. The adherence of G. vaginalis to the epithelial cell line appeared to be mediated by an outer fibrillar coat while adherence to red cells appeared to be mediated by fimbriae. Transmission electron microscopy was performed on the Gardnerella strains used. Thin sections of tissue-culture-adherent strains revealed a dense outer fibrillar coat whereas the surface of the haemagglutinating strains showed fine fimbriae. Negative staining of haemagglutinating strains demonstrated fimbriae on a minority of organisms.

Bacterial Adhesion↗

PubMed1988

A heat shock element in the phosphoglycerate kinase gene promoter of yeast.

The phosphoglycerate kinase (PGK) promoter is often employed in yeast expression vectors due to its very high efficiency. Its activity in unstressed cells has been shown to be due to an upstream activator site (UASPGK) at -402 to -479. Since levels of PGK mRNA can sometimes be elevated by heat shock of yeast cultures this investigation determined how specific deletions of PGK promoter sequences effect levels of PGK mRNA both before and after heat shock. A series of PGK promoter deletions was inserted on a high copy plasmid into cells having a TRP1 gene disruption of the solitary chromosomal PGK locus. This enabled PGK transcripts of plasmid and chromosomal origin to be distinguished by virtue of their different sizes. Certain deletions lacking UASPGK displayed activities that were very low in unstressed cells, but which increased fifty to one-hundred fold after heat shock. With UASPGK present heat shock had only a relatively small or negligible effect on PGK mRNA levels. Heat shock activation was abolished when the -256 to -377 region with homology to the heat shock element consensus of eukaryotes was deleted in addition to UASPGK, but was unaffected by the deletion of regions further downstream containing TATA- and CAAT- sequence motifs. This is the first demonstration of a heat shock element, an activator site normally found upstream of eukaryotic heat shock protein genes, as a natural constituent of a high efficiency glycolytic promoter. It is proposed that PGK may be one member of a small subset of yeast genes that are highly expressed in unstressed cells yet possess a heat shock element to ensure their continued transcription after heat shock.

Base Sequence↗